Part Details

This part replaces:

ITEM CONDITION

AC DELCO 251-663 [WATER PUMP HOUSING GASKET PAIR]

These AC DELCO water pump gaskets are the same parts that you would receive if you purchased from your local GM dealer.

Specifications:

Brand New AC DELCO PARTS

Comes as a PAIR

Includes both gaskets

Enough to do the job on one vehicle

Replaces one of many dealer part numbers including: 12559271, 12588372, 12610311, 251-663

Built to strict quality control standards

Lifetime Warranty

This item is backed by a Limited Lifetime Warranty. In the event this item should fail due to manufacturing defects during intended use, we will exchange the part free of charge (excludes shipping charges) for the original purchaser. Please keep your invoice for proof of this warranty.

Step 1: Remove Intake Tube (1:10)

Start by using an 8 millimeter socket wrench to disconnect the negative battery cable.

Loosen the two clamps by the throttle body and air box.

Use a small flathead screwdriver to break the seal.

Lift the intake tube out.

Step 2: Remove fan shroud (1:50)

Remove the two 10 millimeter bolts with your socket wrench.

Unclip the small hose from the shroud.

Remove pins around fan shroud and gently work hose back and forth to pull fan shroud out.

Step 3: Remove fan (3:00)

Use a large adjustable wrench on the center nut.

Apply force on the wrench to break it loose.

Carefully pull fan out and set aside.

Step 4: Remove serpentine belt (3:30)

Start by double checking that your routing diagram is legible.

Draw out your own if it isn't to save time and confusion later.

Use your socket ratchet to loosen the 15 millimeter bolt located on the tensioner.

Turn your ratchet clockwise to release the tension and remove the belt.

Step 5: Drain radiator and disconnect hoses from water pump (4:33)

Release lower radiator hose and drain fluid into your drain pan.

Use your pliers to slowly squeeze the clamp and pull it back to drain the fluid into your catch pan.

Disconnect radiator hose by loosening and pulling back the clamp.

Use your small flathead screwdriver to gently pry up the hose and wiggle it off.

Make sure any water has drained out of it and set aside. Finally disconnect heater hoses.

Ensure that your catch pan is underneath to catch any water.

Step 6: Remove tension arm (6:40)

Use your wrench to remove the tension arm from the water pump.

Set aside.

Step 7: Remove water neck and remove pump. (6:56)

Use your 10 millimeter socket wrench to remove the two bolts.

Use your torque wrench to remove the six bolts on the water pump.

Then using a sharp razor blade, scrape off any residual gasket material that could create a bad seal.

Step 8: Install 1A Auto water pump (8:18)

Put the new gasket plates on your 1A Auto water pump using the two bolts.

Seat the new pump and place bolts and use your torque wrench to gently snug them up.

Go back and torque them between 22 and 24 foot pounds.

Take the new O-ring that came with your 1A Auto and put it on your thermostat housing.

Step 9: Reassemble (10:10)

Reconnect all your hoses.

Put your belt tensioner back on and put your serpentine belt back on using your diagram.

Reassemble your fan, fan shroud, and intake pipe.

Finally refill with a 50/50 mixture of Dex Cool.

Listen for the sound of any leaks to make sure everything is connected properly.

Finally, reconnect the battery and start up the engine and run it for 30 seconds or so to circulate the coolant.

Double check your level of coolant to make sure it is at the right spot, and you are good to go.